What it is

Cover 4, also called quarters, is a zone defense. Four defenders, the two cornerbacks and the two safeties, each cover one quarter of the field deep.

In a game

Three linebackers cover the short zones, so seven defenders drop into zone. It is very strong against deep passes, and because the safeties start close to the line, they can also help stop the run.

More detail

Cover 4 is often played as a matching coverage: a safety picks up the receiver who runs vertically into his quarter, but can leave to join in on a run. Its weak spots are the short flats and the middle underneath, which offenses attack with quick throws and crossing routes. Teams often use it on third and long, when the offense has to throw deep.

Animated diagram

1. At the snap, both safeties and both cornerbacks drop into the four deep zones, each covering one quarter of the field.
2. Three linebackers drop to the short zones in the middle, so seven defenders cover areas.
3. When four receivers run deep, each one meets a defender who owns that part of the field.